Potassium and chloride channels in freshly isolated rat odontoblasts.
It has been suggested that understanding the physiological properties of odontoblasts may be important in understanding the mechanisms underlying both metabolic and transductive processes in dental pulp. Because ion flux(es) may play a critical role in these events, it is of particular interest to understand ionic mechanisms in odontoblast cells. Thus, the aim of this study was to use patch-clamp recording techniques to examine the properties of resident ion channels in freshly dissociated odontoblasts. In recordings made in potassium-rich solutions, cells displayed at least three distinct channel amplitudes, with conductances of 130 +/- 18 pS, 52 +/- 4 pS, and 25 +/- 2 pS, respectively. Channel activity persisted in the presence of potassium salts of impermeant anions, and could be abolished by barium, a non-specific potassium channel blocker. In addition to the potassium conductances, we saw two separate anion channels in the odontoblast membrane. These channels were predominantly chloride-selective, weakly permeable to both acetate and aspartate, and had conductances of 391 +/- 64 pS and 24 +/- 3 pS. While questions remain regarding the functional role of these and other ion channels that presumably reside in the odontoblast membrane, our results demonstrate that it is possible to study ionic mechanisms of the odontoblast at the level of the single cell.
Guo
L
L
Division of Basic Sciences, New York University College of Dentistry, New York 10010-4086, USA.
Davidson
R M
RM
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000502:physiology*; D003782:Dental Pulp / Q000166:cytology; D003810:Dentinogenesis / Q000502:physiology; D004553:Electric Conductivity; D017136:Ion Transport; D017736:Ion-Selective Electrodes; D009804:Odontoblasts / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D015221:Potassium Channels